Light emitting diode package structure

ABSTRACT

A light-emitting diode package structure including a chip carrier portion, a light-emitting diode chip, and a package material is provided. The light-emitting diode chip is disposed on the chip carrier portion of the package. The package material is filled in the chip carrier portion and covers the light-emitting diode chip. The package material includes a matrix material, a plurality of first powder particles, and a plurality of second powder particles. The first powder particles and the second powder particles are distributed in the matrix material. Each first powder particle is a wavelength conversion material. Each second powder particle has a shell-like structure.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of U.S. provisionalapplication Ser. No. 61/818,889, filed on May 2, 2013 and Taiwanapplication serial no. 103100061, filed on Jan. 2, 2014. The entirety ofeach of the above-mentioned patent applications is hereby incorporatedby reference herein and made a part of this specification.

TECHNICAL FIELD

The disclosure relates to a light-emitting diode package structure.

BACKGROUND

Powder particles can provide a variety of functions by controlling theparticle size or changing the material thereof. Moreover, powderparticles have the characteristic of easy processing, and therefore theapplications of powder particles are quite extensive. For instance,common goods such as paint, cosmetic, and detergent all achieve thedesired effect with powder particles. Moreover, in the field ofelectronic products, the application of powder particles is even moreextensive. Using a light-emitting diode package structure as an example,the wavelength conversion material used in the light-emitting diodepackage structure is powder particles.

Specifically, the fabrication method of the light-emitting diode packagestructure generally includes first disposing a light-emitting diode chipon a dock or a chip carrier portion, and then forming a wavelengthconversion layer on the light-emitting diode chip with a method of moldglue injection on the dock. In particular, the wavelength conversionlayer mainly uses a colloid material as a carrier to carry thewavelength conversion material of the powder particles so as tofacilitate the glue injection step. However, in the glue injection step,the wavelength conversion material of the powder particles is subsidedin the colloid material due to gravitational force, such that thewavelength conversion material has a concentration gradient distributionin a direction perpendicular to the light-emitting surface of the chip.As a result, the color temperature of the light-emitting diode packagestructure cannot be precisely controlled. Similarly, in otherapplications, the subsidence effect of the powder particles in thematrix material often causes the product to fail to meet desiredspecifications.

SUMMARY

The disclosure provides a light-emitting diode package structure,wherein a package material thereof is composed of at least two powderparticles. The powder particles are not excessively concentrated on thebottom portion in the package material.

The light-emitting diode package structure of the disclosure includes achip carrier portion, a light-emitting diode chip, and a packagematerial. The light-emitting diode chip is disposed on the chip carrierportion of the package. The package material is filled in the chipcarrier portion and covers the light-emitting diode chip. The packagematerial includes a matrix material, a plurality of first powderparticles, and a plurality of second powder particles. The first powderparticles and the second powder particles are distributed in the matrixmaterial. Each first powder particle is a wavelength conversionmaterial, and each second powder particle has a shell-like structure.

To make the above features and advantages of the disclosure morecomprehensible, several embodiments accompanied with drawings aredescribed in detail as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of this specification. The drawings illustrate embodiments of thedisclosure and, together with the description, serve to explain theprinciples of the disclosure.

FIG. 1A is a schematic diagram of a powder particle distributed in amatrix material.

FIG. 1B is a schematic diagram of a composite particle.

FIG. 2 is a schematic diagram of the process of a preparation method ofa composite material according to an embodiment of the disclosure.

FIG. 3A to FIG. 3B are schematic diagrams of a preparation method of acomposite material according to another embodiment of the disclosure.

FIG. 4A to FIG. 4C are schematic diagrams of various compositematerials.

FIG. 5 is a schematic diagram of a composite material according to anembodiment of the disclosure.

FIG. 6 is a schematic diagram of a composite material according toanother embodiment of the disclosure.

FIG. 7 is a schematic diagram of a composite material according toanother embodiment of the disclosure.

FIG. 8 is a schematic diagram of a composite material according toanother embodiment of the disclosure.

FIG. 9 is a schematic diagram of a conventional light-emitting diodepackage structure.

FIG. 10 is a cross-sectional schematic diagram of a light-emitting diodepackage structure according to the first embodiment of the disclosure.

FIG. 11 is a schematic diagram of a light-emitting diode packagestructure according to the second embodiment of the disclosure.

FIG. 12 is a distribution diagram of light emitted by a plurality ofconventional light-emitting diode package structures in CIE colorcoordinates.

FIG. 13 is a distribution diagram of light emitted by a plurality oflight-emitting diode package structures according to the firstembodiment of the disclosure in CIE color coordinates.

FIG. 14 is a distribution diagram of light emitted by a plurality oflight-emitting diode package structures according to another embodimentof the disclosure in CIE color coordinates in which first powderparticles and second powder particles are not bonded but are alluniformly distributed in a matrix material.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

FIG. 1A is a schematic diagram of a powder particle distributed in amatrix material. Referring to FIG. 1A, when a powder particle 10 isdistributed in a matrix material 12, the forces that the powder particle10 is subjected to substantially include a gravitational force Fg of thepowder particle 10 itself, a buoyancy force Fb of the matrix material12, and a fluid resistance Fh generated when the powder particle 10 ismoved in the matrix material 12. In general, the direction of thegravitational force Fg is opposite to the direction of each of thebuoyancy force Fb and the fluid resistance Fh, and the sum of the threeforces determines whether the powder particle 10 is sunk or suspended inthe matrix material 12. The matrix material 12 can be a fluid materialsuch as silicone oil, or an uncured colloid material such as silica gel,but is not limited thereto.

When the gravitational force Fg of the powder particle 10 is greaterthan the sum of the buoyancy force Fb and the fluid resistance Fh, thepowder particle 10 is subsided and cannot be suspended in the matrixmaterial 12, which is a common issue when the powder particle 10 isused. When the density of the powder particle 10 is greater than thedensity of the matrix material 12, the issue of subsidence is often notreadily overcome. Therefore, in an embodiment of the disclosure below,how the powder particle 10 overcomes the issue of subsidence and theapplication of the anti-subsidence powder particle are described.

The following descriptions are all embodiments based on the spirit ofthe disclosure and are not intended to limit the specific means anddetails of the disclosure.

If a shell 14 having a low density is connected to the surface of thepowder particle 10 as shown in FIG. 1B, then a composite particle 10A isformed, wherein by adjusting the particle size or quantity of the shell14, the equivalent density of the composite particle 10A can beadjusted. If the density of the powder particle 10 is d1, the weight ofthe powder particle 10 is m1, and the volume of the powder particle 10is v1, and the density of the shell 14 is d2, the weight of the shell 14is m2, and the volume of the shell 14 is v2, then after the powderparticle 10 and the shell 14 are bonded to form the composite particle10A, the equivalent density of the composite particle 10A isd3=(m1+m2)/(v1+v2). In other words, the equivalent density of thecomposite particle 10A is necessarily less than the density of thepowder particle 10. The method is used in the present embodiment toadjust the density of the composite particle so as to achieve thepurpose of balancing gravitational force and buoyancy force.

FIG. 2 is a schematic diagram of the fabrication process of a compositematerial, wherein an embodiment of the preparation method of thecomposite material is as follows:

Step S01: a first power particles and a second powder particles areuniformly mixed;

Step S02: tetraethyl orthosilicate (TEOS) and an alcohol solution areuniformly mixed, wherein the alcohol solution contains water (H₂O) andthe water can be reacted with TEOS, and the function of the alcohol isto uniformly mix the TEOS in oil phase and the H₂O in water phase. Insuch a mixing process, the alcohol does not participate in the reaction.Therefore, the reaction formula of the above mixing process is asfollows:

Si(OC₂H₅)₄+H₂O→Si(OH)₄+4C₂H₅OH

Step S03: the mixed powder particles of S01 is mixed into the mixedsolution of TEOS and alcohol solution. In this step, TEOS and thealcohol are reacted to produce Si(OH)₄ colloids, which are colloidsformed by the linking of Si(OH)₄. An ammonia solution can further beadded such that the reaction of Si(OH)₄ to form SiO₂ is accelerated,wherein the ammonia solution is a catalyst and does not participate inthe reaction. The reaction formula in which the ammonia solution is usedas a catalyst can be presented as follows:

Si(OH)₄+Si(OH)₄→NH₄OH→SiO₂+H₂O

Step S04: the remaining water (H₂O) and the resulting alcohol (C₂H₅OH)are removed with high-temperature baking to form a thin film(SiO₂),wherein the thin film is used to bond the first powder particles and thesecond powder particles.

FIG. 3A to FIG. 3B are schematic diagrams of a preparation method of acomposite material according to another embodiment of the disclosure.Referring to FIG. 3A, in the preparation method of a composite materialprovided in the present embodiment, a coupling agent 22 can first beprovided, and a plurality of first powder particles 24 are mixed in thecoupling agent 22. Here, the coupling agent 22 is TEOS, but can also besodium silicate (Na₂SiO₃.nH₂O) or the like. The first powder particles24 can be selected based on actual application requirements, and are,for instance, a wavelength conversion material, a pigment, a dye, orother powder materials. The coupling agent 22 (TEOS) can be mixed withwater, butanol, or ethanol, and then the first powder particles 24 areadded to the coupling agent 22 mixed with water. The coupling agent 22forms a laminar colloid on the surface of the first powder particles 24through a hydrolysis reaction, wherein the laminar colloid formed by thecoupling agent 22 is used as a binding agent 26. In the presentembodiment, when the coupling agent 22 is TEOS, the binding agent 26 issilicon dioxide, and the ammonia solution catalyst can be added to thehydrolysis reaction of the coupling agent to accelerate the productionof silicon dioxide.

Next, referring to FIG. 3B, a second powder particle 28 is added to themixture of the coupling agent 22 and the first powder particles 24. Thesecond powder particle 28 can be bonded with at least one first powderparticle 24 through the binding agent 26 to form a composite particle20. In the present embodiment, the second powder particle 28 has ashell-like structure, and can be a hollow shell. Here, the shellincludes silicon oxide, aluminum oxide, titanium oxide, chromium oxide,or a combination thereof. Moreover, in other embodiments, a corematerial can be filled inside the shell to form the second powderparticle 28, wherein the core material can be magnetic or be driven byan electric field.

After the composite particle 20 is formed, a baking step is performed toremove the resulting water and alcohol so as to obtain a dried compositeparticle 20. In the mixing process of FIG. 3B, the first powderparticles 24 and the second powder particle 28 can be bonded togetherthrough various methods. As a result, the composite particle 20 can havevarious configurations, wherein FIG. 4A to FIG. 4C are schematicdiagrams of several composite particles. In FIG. 4A, a compositeparticle 20A can be formed by bonding a first powder particle 24 and asecond powder particle 28, and the binding agent 26 is used to connectthe first powder particle 24 and the second powder particle 28. In FIG.4B, a composite particle 20B can be formed by bonding a plurality offirst powder particles 24 and a second powder particle 28, and thebinding agent 26 is used to connect the first powder particles 24 andthe second powder particle 28. In FIG. 4C, a composite particle 20C isformed by bonding at least one first powder particle 24 and at least onesecond powder particle 28, and the binding agent 26 encapsulates thefirst powder particle 24 and the second powder particle 28 at the sametime to form a cover layer 26a of the composite particle 20C. In otherwords, in addition to being used to connect the first powder particle 24and the second powder particle 28, the binding agent 26 can also be usedto cover the first powder particle 24 and the second powder particle 28together.

In the present embodiment, the second powder particle 28 has ashell-like structure. The second powder particle 28 is a hollow shell.In the present embodiment, by bonding the second powder particle 28 andthe first powder particle 24, the equivalent density of each ofcomposite particles 20, 20A, 20B, and 20C can be less than the densityof the first powder particle 24. Therefore, the composite particles 20,20A, 20B, and 20C of the present embodiment are more readily suspendedin a fluid or an uncured matrix with respect to the first powderparticle 24, which is beneficial to the application of the compositeparticles 20, 20A, 20B, and 20C in powder state.

FIG. 5 is a schematic diagram of a composite material according to anembodiment of the disclosure. Referring to FIG. 5, a composite material30 of the present embodiment includes a plurality of composite particles34 distributed in a matrix material 32, wherein the composite particles34 are fabricated by the preparation method of the embodiments above. Asa result, the composite particles 34 can be formed by at least one ofthe composite particles 20, 20A, 20B, and 20C. Each composite particle34 is formed by bonding at least one first powder particle 24 and atleast one second powder particle 28, wherein each second powder particle28 is a hollow shell.

In general, the matrix material 32 has a first density, the first powderparticles 24 have a second density, and the second density is greaterthan the first density. When the first powder particles 24 having agreater density are mixed in the matrix material 32 having a smallerdensity, the first powder particles 24 are readily subsided due togravitational force (as shown in FIG. 1).

In the present embodiment, second powder particles 28 are provided,wherein the second powder particles 28 have a hollow shell structure,and when the first powder particles 24 and the second powder particles28 are bonded to form the composite particles 34, the compositeparticles 34 have a third density. Here, by adjusting the particle size,thin-shell thickness, and quantity of the second powder particles 28,the third density can be about equal to the first density of the matrixmaterial 32 such that the composite particles 34 can be uniformlydistributed in the matrix material 32, thus further alleviating theissue of subsidence of the first powder particles 24 in the matrixmaterial 32. The third density of the composite particles 34 issubstantially related to the equivalent density after the first powderparticles 24 and the second powder particles 28 are bonded.

In an embodiment, the composite particles 34 can be hydrophobic, and thematrix material 32 can be nonpolar or hydrophobic, such that thecomposite particles 34 can be uniformly distributed in the matrixmaterial 32. Similarly, when the composite particles 34 are hydrophilic,the matrix material is nonpolar or hydrophilic. More specifically, thecomposite particles 34 have the same polarity as the matrix material 32.

In an embodiment, the matrix material 32 is a colloid material, and thefirst powder particles 24 include a wavelength conversion material,wherein the matrix material 32 has a first density of 1 g/cm³ to 2.5g/cm³, and the first powder particles 24 have a second density rangingfrom 2.5 g/cm³ to 6 g/cm³. To uniformly distribute all of the compositeparticles 34 in the matrix material 32, the density of the second powderparticles 28 can range from 0.01 g/cm³ to 2 g/cm³, the second powderparticles 28 can account for 0.5% to 100% in the total (volume) amountof the first powder particles 24 and the second powder particles 28, andthe third density of the composite particles 34 ranges from 1 g/cm³ to1.5 g/cm³. The materials and numeric values above are only exemplary,and are not intended to limit the disclosure. In other embodiments, thefirst powder particles 24 can be a dye, a pigment, or other particulatematerials.

FIG. 6 is a schematic diagram of a composite material according toanother embodiment of the disclosure. Referring to FIG. 6, a compositematerial 40 contains a plurality of first powder particles 44 and aplurality of second powder particles 46. The first powder particles 44and the second powder particles 46 are mixed in a matrix material 42.The matrix material 42 has a first density, the first powder particles44 have a second density, and the second density is greater than thefirst density. The second powder particles 46 have a shell-likestructure and the second powder particles 46 are substantially hollowshells.

According to the schematic diagram of forces of FIG. 1A, the seconddensity of the first powder particles 44 is greater than the firstdensity of the matrix material 42 such that the first powder particles44 are readily subsided in the matrix material 42 due to gravitationalforce. Since the second powder particles 46 have a hollow structure, byadjusting the particle size of the second powder particles 46, theequivalent density thereof can be no greater than that of the matrixmaterial 42 such that the second powder particles 46 are uniformlydistributed in the matrix material 42. Therefore, when the first powderparticles 44 are subsided in the matrix material 42, the second powderparticles 46 can stop the subsidence of the first powder particles 44such that the first powder particles 44 are suspended in the matrixmaterial 42. In the present embodiment, the material and density of eachof the matrix material 42, the first powder particles 44, and the secondpowder particles 46 are as described in the embodiments above and arenot repeated herein.

In the embodiments above, the second powder particles are allexemplified by having hollow structures, but the disclosure is notlimited thereto. In other embodiments, a core material can be filledinside the second powder particles, wherein the core material is, forinstance, a magnetic material. In the present embodiment, by bonding thesecond powder particles and the first powder particles, the compositeparticles can be moved by a magnetic field or an electric field. FIG. 7is a schematic diagram of a composite material according to anotherembodiment of the disclosure. Referring to FIG. 7, a composite material50 includes a plurality of first powder particles 54 and a plurality ofsecond powder particles 56. The first powder particles 54 and the secondpowder particles 56 are mixed in a matrix material 52. The matrixmaterial 52 has a first density, the first powder particles 54 have asecond density, and the second density is greater than the firstdensity. The second powder particles 56 have a shell-like structure andinclude a shell 56A and a core material 56B, wherein the core material56B is filled in the shell 56A. Moreover, at least one first powderparticle 54 and at least one second powder particle 56 are bondedtogether to form a composite particle 58, wherein the at least one firstpowder particle 54 and the at least one second powder particle 56 can bebonded together by the preparation method of FIG. 2 or FIG. 3A to FIG.3B.

In the present embodiment, the core material 56B is magnetic. Therefore,the composite particles 58 can be moved in the matrix material 42 byapplying a magnetic field B. As a result, by applying the magnetic fieldB, regardless of whether the density of each of the first powderparticles 54 and the second powder particles 56 is less than that of thematrix material 52, the first powder particles 54 and the second powderparticles 56 can both be suspended or uniformly distributed in thematrix material 52 and not be subsided on the bottom portion.

FIG. 8 is a schematic diagram of a composite material according to yetanother embodiment of the disclosure. Referring to FIG. 8, a compositematerial 60 includes a plurality of first powder particles 54 and aplurality of second powder particles 56. The first powder particles 54and the second powder particles 56 are distributed in a matrix material52. In the present embodiment, the density and properties of each of thematrix material 52, the first powder particles 54, and the second powderparticles 56 are as described for FIG. 7 and are not repeated herein.However, the first powder particles 54 and the second powder particles56 of the present embodiment are respectively distributed in the matrixmaterial 52 and are not bonded together.

In the present embodiment, the core material 56B is magnetic. Therefore,the second powder particles 56 can be moved in the matrix material 52 byapplying the magnetic field B. As a result, by applying the magneticfield B, the second powder particles 56 can be suspended in the matrixmaterial 52. In the present embodiment, the first powder particles 54are stopped by the second powder particles 56 when subsiding, andtherefore the first powder particles 54 can be suspended in the matrixmaterial 52. In other words, regardless of whether the gravitationalforce sustained by the first powder particles 54 and the second powderparticles 56 is greater than the sum of the buoyancy force and fluidresistance, by applying the magnetic field B, the first powder particles54 and the second powder particles 56 can both be suspended in thematrix material 52 and not be subsided on the bottom portion.

Each embodiment above provides a method of preventing powder particlesfrom subsiding in a matrix material. To further describe the disclosure,a light-emitting diode package structure and relevant components thereofare exemplified below to describe the application of the compositeparticles and the composite material. Of course, the application methodbelow is only exemplary and is not intended to limit the technical fieldand specific conditions applied in the disclosure.

FIG. 9 is a schematic diagram of a conventional light-emitting diodepackage structure. Referring to FIG. 9, a light-emitting diode packagestructure 300 includes a chip carrier portion 310, a light-emittingdiode chip 320, and a package material 330. The light-emitting diodechip 320 is disposed on the chip carrier portion 310, and the packagematerial 330 is filled in the chip carrier portion 310 and covers thelight-emitting diode chip 320. The package material 330 includes amatrix material 332 and a plurality of wavelength conversion powderparticles 334, wherein the matrix material 332 can be a package colloid.As shown in the figure, the wavelength conversion powder particles 334are collectively distributed in the bottom portion of the matrixmaterial 332. In other words, the wavelength conversion powder particles334 are also subsided in the matrix material 332 due to gravitationalforce, thus causing light rays emitted by a light-emitting diode to notbe uniformly distributed.

FIG. 10 is a cross-sectional schematic diagram of a light-emitting diodepackage structure according to the first embodiment of the disclosure.Referring to FIG. 10, a light-emitting diode package structure 100includes a chip carrier portion 110, a light-emitting diode chip 120,and a package material 130. The light-emitting diode chip 120 isdisposed on the chip carrier portion 110. The package material 130 isfilled in the chip carrier portion 110 and covers the light-emittingdiode chip 120. The package material 130 includes a matrix material 132,a plurality of first powder particles 134, and a plurality of secondpowder particles 136. The first powder particles 134 are distributed inthe matrix material 132, wherein the first powder particles 134 includea wavelength conversion material. The second powder particles 136 arealso distributed in the matrix material 132, wherein the second powderparticles 136 have a shell-like structure. Here, the light-emittingdiode chip 120 can be disposed on the chip carrier portion 110 by aknown method such as a method of flip-chip bonding.

In the present embodiment, the matrix material 132 is a package colloidmaterial and includes epoxy resin, silica gel, or glass. Moreover, thedensity of the matrix material 132 is about 1 g/cm³ to 2.5 g/cm³ whenuncured. The first powder particles 134 include a wavelength conversionmaterial, and the density thereof is about 2.5 g/cm³ to 6 g/cm³, whichis greater than the density of the uncured matrix material 132. If thefirst powder particles 134 are directly added to the uncured matrixmaterial 132, then the first powder particles 134 are readily subsidedin the matrix material 132.

Therefore, the package material 130 further includes the second powderparticles 136, wherein the second powder particles 136 have a shell-likestructure, thus helping to prevent subsidence of the first powderparticles 134 in the matrix material 132 during the fabrication process.As a result, the difference in distribution density of the compositeparticles (formed by the first powder particles 134 and the secondpowder particles 136 bonded together) distributed in two differentregions of the matrix material 132 is less than 15%, and the differencein distribution density can even be 3% or less. The second powderparticles 136 can optionally have light scattering or light reflectionproperties, and can have high transmittance for visible light, such as alight transmittance of greater than 70%, preferably greater than 80%, soas to improve the light extraction efficiency of the light-emittingdiode package structure 100. In the present embodiment, the particlesize of the second powder particles 136 ranges from 0.01 μM to 100 μmand the second powder particles 136 account for 0.5% to 100% of thetotal weight of the first powder particles 134 and the second powderparticles 136.

As shown in FIG. 10, to reduce the occurrence of or to prevent the firstpowder particles 134 from subsiding in the matrix material 132, thefirst powder particles 134 and the second powder particles 136 can firstbe prepared into composite particles by the above method. Then, thecomposite particles and the uncured matrix material 132 are mixed toform a composite material, and then the composite material is formed onthe light-emitting diode chip 120 through a method such as dispensing,instillation, or coating. Lastly, the composite material is cured toform the package material 130.

In the present embodiment, the second powder particles 136 can be hollowshells as shown in FIG. 5. When the second powder particles 136 aresilicon oxide, the density thereof is, for instance, 0.01 g/cm³ to 2g/cm³. Moreover, the equivalent density of the composite particlesformed by bonding the first powder particles 134 and the second powderparticles 136 is about 1 g/cm³ to 1.5 g/cm³, which is close to thedensity of the uncured matrix material 132. As a result, the compositeparticles can be uniformly distributed in the uncured matrix material132. The binding agent used for bonding the first powder particles 134and the second powder particles 136 can have high transmittance forvisible light, such as a transmittance of greater than 70%, preferablygreater than 80%. In the present embodiment, the index of refractionthereof is substantially close to the index of refraction of the matrixmaterial. For instance, when the matrix material is a package colloid,the index of refraction of the package colloid ranges from 1.4 to 1.6,and the index of refraction of the binding agent can range from 1.0 to2.0.

In another embodiment, the shell structure of the second powderparticles 136 can have a core material, wherein the core material ismagnetic, such that a magnetic field can be applied when the compositeparticles and the uncured matrix material 132 are mixed so as to suspendthe composite particles. As a result, the composite particles can beuniformly distributed in the matrix material 132. In the presentembodiment, the equivalent density of the composite particles can be notlimited to being less than or equal to the density of the uncured matrixmaterial 132.

Moreover, in other embodiments, the first powder particles 134, thesecond powder particles 136, and the uncured matrix material 132 canalso be prepared by the method of FIG. 6 or FIG. 8.

FIG. 11 is a schematic diagram of a light-emitting diode packagestructure according to the second embodiment of the disclosure.Referring to FIG. 11, a light-emitting diode package structure 200includes a chip carrier portion 210, a light-emitting diode chip 220,and a package material 230. The light-emitting diode chip 220 isdisposed on the chip carrier portion 210, and the package material 230is filled in the chip carrier portion 210 and covers the light-emittingdiode chip 220. The package material 230 includes a matrix material 232,a plurality of first powder particles 234, and a plurality of secondpowder particles 236, wherein the matrix material 232 is a packagecolloid, the first powder particles 234 are distributed in the matrixmaterial 232, and the first powder particles 234 include a wavelengthconversion material. The second powder particles 236 are alsodistributed in the matrix material 232. At the same time, the secondpowder particles 236 have a shell-like structure.

The difference between the present embodiment and the embodiment of FIG.10 is that, the package material 230 of the present embodiment has apowder concentrated portion 230A and a powder sparse portion 230B,wherein the powder sparse portion 230B is located between thelight-emitting diode chip 220 and the powder concentrated portion 230A.In other words, the distribution density of each of the first powderparticles 234 and the second powder particles 236 in the powderconcentrated portion 230A is greater than the distribution densitythereof in the powder sparse portion 230B. The first powder particles234 and the second powder particles 236 can be prepared into compositeparticles by the methods of FIG. 2 and FIG. 3, wherein the equivalentdensity of the composite particles is less than the density of thematrix material 232 when uncured. Therefore, the composite particles canbe suspended on the surface of the uncured matrix material 232 and becollectively distributed in the powder concentrated portion 230A.

FIG. 12 is a distribution diagram of light emitted by a plurality ofconventional light-emitting diode package structures in CIE(International Commission on Illumination) color coordinates. FIG. 13 isa distribution diagram of light emitted by a plurality of light-emittingdiode package structures according to the first embodiment of thedisclosure in CIE color coordinates. FIG. 14 is a distribution diagramof light emitted by a plurality of light-emitting diode packagestructures according to another embodiment of the disclosure in CIEcolor coordinates in which first powder particles and second powderparticles are not bonded but are all uniformly distributed in a matrixmaterial. In FIGS. 12-14, X and Y respectively represent the axes, thetriangle symbols represent the positions of light emitted by eachlight-emitting diode package structure in CIE color coordinates beforethe matrix material is cured, and the square symbols represent thepositions of light emitted by each light-emitting package structure inCIE color coordinates after the matrix material is cured.

It can be known from FIG. 12 that, the distribution of light emitted bya conventional light-emitting diode package structure in CIE colorcoordinates before and after the matrix material is cured issignificantly different. For instance, the distribution in CIE colorcoordinates is concentrated in region I before the matrix material iscured, and the distribution in CIE color coordinates is concentrated inregion II after the matrix material is cured. It can be known from FIG.13 that, on the other hand, the distribution of light emitted by thelight-emitting diode package structure according to the first embodimentof the disclosure in CIE color coordinates is relatively concentratedbefore and after the matrix material is cured. As shown in the figure,the distribution in CIE color coordinates is concentrated in region IIIbefore the matrix material is cured, and the distribution in CIE colorcoordinates is concentrated in region IV after the matrix material iscured. It can be known from FIG. 14 that, the distribution of lightemitted by the light-emitting diode package structure according toanother embodiment of the disclosure in CIE color coordinates isrelatively concentrated before and after the matrix material is cured.As shown in the figure, the distribution in CIE color coordinates isconcentrated in region V before the matrix material is cured, and thedistribution in CIE color coordinates is concentrated in region VI afterthe matrix material is cured. It can be known from the above that, themeans of the embodiments of the disclosure for alleviating the issue ofsubsistence through the disposition of the second powder particles canresult in a light-emitting diode package structure having consistentlight colors.

In FIG. 12, since the first powder particles are subsided, the colorcoordinates of light emitted by the light-emitting diode packagestructure are shifted from region I to region II, thus causing deviationof light colors. Therefore, to make the light emitted by thelight-emitting diode package structure be more concentrated in the colorcoordinates, a colloid material mixed with composite particles can beused for compensation, such that the light colors originally in regionII are returned to region I.

Based on the above, the disclosure proposes mixing or bonding firstpowder particles and second powder particles having a shell-likestructure to form composite particles so as to reduce the occurrence ofor to prevent the first powder particles from subsiding in a matrixmaterial. The preparation method of the embodiments of the disclosure orthe use of the composite material of the embodiments of the disclosurefor fabricating the package material of a light-emitting diode packagestructure helps to increase consistency of light colors of thelight-emitting diode package structure.

What is claimed is:
 1. A light-emitting diode package structure,comprising: a package having a chip carrier portion; a light-emittingdiode chip disposed on the chip carrier portion of the package; and apackage material disposed on the chip carrier portion and covering thelight-emitting diode chip, wherein the package material comprises: amatrix material; a plurality of first powder particles distributed inthe matrix material, wherein each first powder particle is a wavelengthconversion material; and a plurality of second powder particlesdistributed in the matrix material, wherein each second powder particlehas a shell-like structure.
 2. The light-emitting diode packagestructure of claim 1, wherein at least one of the first powder particlesis bonded to at least one of the second powder particles to form acomposite particle.
 3. The light-emitting diode package structure ofclaim 2, wherein the matrix material has a first density when uncured,the composite particle has a second density, and the second density isnot greater than the first density.
 4. The light-emitting diode packagestructure of claim 3, wherein a number of the composite particle is aplural, and the composite particles are uniformly distributed in thematrix material such that a difference in distribution density of thecomposite particles distributed in two different regions of the matrixmaterial is not greater than 15%.
 5. The light-emitting diode packagestructure of claim 3, wherein the package material has a powderconcentrated portion and a powder sparse portion, and a distributiondensity of each of the first powder particles and the second powderparticles in the powder concentrated portion is greater than adistribution density of each thereof in the powder sparse portion. 6.The light-emitting diode package structure of claim 2, wherein at leastone of the first powder particles is bonded to at least one of thesecond powder particles through a binding agent.
 7. The light-emittingdiode package structure of claim 6, wherein a light transmittance of thebinding agent is greater than 70%.
 8. The light-emitting diode packagestructure of claim 6, wherein the binding agent covers at least one ofthe first powder particles and at least one of the second powderparticles.
 9. The light-emitting diode package structure of claim 6,wherein the composite particle and the matrix material have the samepolarity.
 10. The light-emitting diode package structure of claim 6,wherein the binding agent comprises silicon oxide, silicate, titaniumoxide, zinc oxide, tantalum oxide, aluminum oxide, or a combinationthereof.
 11. The light-emitting diode package structure of claim 1,wherein a light transmittance of the second powder particles is greaterthan 70%.
 12. The light-emitting diode package structure of claim 1,wherein each second powder particle comprises a shell.
 13. Thelight-emitting diode package structure of claim 12, wherein each secondpowder particle further comprises a core material filled in the shell.14. The light-emitting diode package structure of claim 13, wherein thecore material is magnetic.
 15. The light-emitting diode packagestructure of claim 12, wherein the shell comprises silicon oxide,aluminum oxide, titanium oxide, chromium oxide, or a combinationthereof.
 16. The light-emitting diode package structure of claim 1,wherein a particle size of each second powder particle ranges from 0.01μm to 100 μm.
 17. The light-emitting diode package structure of claim 1,wherein the matrix material is a colloid material.
 18. Thelight-emitting diode package structure of claim 1, wherein the secondpowder particles account for 0.5% to 10% of a total weight of the firstpowder particles and the second powder particles.
 19. The light-emittingdiode package structure of claim 1, wherein a density of the secondpowder particles is not greater than a density of the matrix materialwhen uncured.
 20. The light-emitting diode package structure of claim 1,wherein the package material has a powder concentrated portion and apowder sparse portion, the powder sparse portion is located between thelight-emitting diode chip and the powder concentrated portion, and adistribution density of each of the first powder particles and thesecond powder particles in the powder concentrated portion is greaterthan a distribution density of each thereof in the powder sparseportion.